Self-venting drainage system for body fluids



SELF-VENTING DRAINAGE SYSTEM FOR BODY FLUIDS Filed July 26, 1965 R. E.ERICSON Feb. 25, 1969 Sheet of 5 1 lllllllllllllll I;

R. E. Emcsom 3,429,314

SELF-VENTING DRAINAGE SYSTEM FOR BODY FLUIDS Feb. 25, 19%9 Filed July26, i965 x 1., v E

. 25, W69 R. E. ERICSON 3,429,314

SELF-VENTING DRAINAGE SYSTEM FOR BODY FLUIDS Filed July 26. 1965 Sheet 3of 5 3,429,314 SELF-VENTING DRAINAGE SYSTEM FOR BODY FLUIDS Richard E.Ericson, Barrington, Ill., assignor to The Kendall Company, Boston,Mass., a corporation of Massachusetts Filed July 26, 1965, Ser. No.474,650

US. Cl. 128349 13 Claims Int. Cl. A61m 25/00; A61f /44 ABSTRACT OF THEDISCLOSURE A body-fluid gravitational drainage system, such as a urinarycatheter, for draining fluids from a body cavity by gravitational means,wherein the drainage channel is vented to the atmosphere during use soas to prevent development of a negative pressure within the body cavityand thus avoid damage to 'body tissue within the cavity. A bacterialfilter unit which allows passage of air but not passage of body fluids,is positioned in the vent to filter the air entering the vent and toprevent leakage of body fluid through the vent, whether the filter beabove or below the body cavity fluid level.

This invention is concerned with animal body-fluid drainage systems inwhich a tubing portion for positioning within the body is an essentialpart and in which a bacterial filter normally operative both below andabove the bodyfluid level permits bacteria-free air to break thenegative pressure created by the body-fluid column in the system.

It has been discovered pathologically that when tubing, as for instancean indwelling catheter, is utilized for body fluid drainage bygravitation means, a column of body fluid is formed in the drainagesystem which persists after the fluid source is drained. This column offluid creates a suction, drawing the adjacent tissue such as, forinstance, bladder mucosa into the drainage eyes of the indwellingcatheter. The amount of suction is dependent upon the height of thefluid (such as urine) column. A column of fluid having a vertical dropof as little as six inches causes pseudo polyps to form in the adjacenttissue, such as bladder mucosa, at times causing denudation of theepithelium tissue and at times a hemorrhagic condition, Obviously, wheredenudation of the normal protective tissue, such as mucosa of thebladder, occurs, bacterial penetration and invasion is very much moreprobable.

In US. Patent No. 3,114,373 which relates to a gastrointestinal sumptube assembly, the possibility that mucosal surfaces may be drawn intothe tube lumen and thus damage by suction from a high volume, low vacuumaspirator is recognized. An open tube is provided to draw in ambientair.

It is also generally recognized that ambient air contains bacteria.Thus, in the administration of parenteral fluids it has been thepractice to vent the bottles containing these fluids through a bacterialfilter so that the fluids will flow. At times very simple filters suchas a wad of cotton in a tube above the fluid level have been used. Themost recent practice has been concerned with providing bottom filterswhich bubble filtered air up through the parenteral fluids. A filter ofthis latter type is illustrated and described in Canadian Patent No.712,875, issued July 6, 1965 to Abbott Laboratories, North Chicago,111., upon an invention by Albert P. Bujan.

But worthwhile as these inventions are, they have not been concernedwith the drainage of body fluids by gravitational means and until thisinvention no one had provided an adequate solution of how to drain suchfluids without tissue damage in all of the various attitudes of patientswhether prone, supine, sedent or ambulatory.

"nited States atent O i It is an object of this invention to provide abody fluid drainage system in which an effective bacterial air filterbreaks the negative pressure created by the body fluid column whetherthe filter be above or below the body cavity fluid level.

It is a further object of this invention to provide a body fluiddrainage system in which the bacterial air filter may be readilyexchanged if it becomes inoperative without removal of the drainagetubing.

Other objects of the invention will be apparent from an examination ofthe drawings in which:

FIGURE 1 represents a typical fluid drainage system in which a bacterialfilter forming a portion of a urinary catheter connects with a separatechannel terminating in use within the bladder.

FIGURE 2 is a longitudinal section of the tip of the catheter of FIGURE1.

FIGURE 3 is a modification of FIGURES 1 and 2 in which the channelconnecting with the bacterial filter connects with the drainage channelof the catheter at a point longitudinally outward of the catheterdrainage eye.

FIGURE 4 is a further modification of FIGURES 1 and 2 in that thechannel connecting with the bacterial filter joins the drainage channelof the catheter externally of the patients body and the filter is ascrew-on type.

FIGURE 5 is a modification of FIGURE 4 in that the bacterial filter unitis attached by forcing the connecting tube into the open filter end.

FIGURE 6 is a further modification of FIGURES 4 and 5 in that the filtercovers a hole opening directly into the catheter drainage channelexteriorly of the body.

FIGURE 7 is a longitudinal partial section of FIG- URE 6 showing thefilter sealed in position.

FIGURE 8 illustrates, in partial longitudinal section, a filter assemblynot integral with the catheter but which connects with the drainagechannel of a normal retention catheter such as the Foley urinarycatheter.

FIGURE 9 illustrates in longitudinal section a drainage channel with acombination needle-penetrating plug and end plug showing the filter inplace with its needle penetrating the plug.

FIGURE 10 illustrates a bacterial maze in which the bacteria are trappedin the breather tube convolutions.

FIGURE 11 illustrates a typical filter unit of the invention in which awad type bacterial filter whose functionality is limited or destroyed byurine or other body fluid is contained in a fluid impervious but airpervious cup.

For purposes of this invention fluid impervious is intended to describethat characteristic or a porous material which under a head of up to 10inches of body fluid will not leak nor wet out sufliciently to preventpassage of air therethrough.

FIGURE 12 illustrates a filter unit similar to that of FIGURE 10 butwith a sheet filter substituted for the wad type filter.

FIGURE 13 illustrates an impervious cylinder into which a plug ofmaterial, such as open cell foam, is

forced which with a filter provides a filter unit which will pass airbut not urine or other :body fluids.

In FIGURE 14 is shown a filter unit in which the urine or other bodyfluid is in contact with the filter on one side with ambient air on theother side.

FIGURE 15 illustrates a fail-safe filter unit in which a second filtercomes into action if the first becomes inoperative.

FIGURE 16 illustrates a simple apparatus for determining whether afilter may be used in direct contact with urine or other body fluids.

FIGURE 17 shows the typical filter holder illustrated in FIGURE 16 incross section.

I have discovered that while some bacterial filters are operative onlywhen they are relatively dry, others are effective as well with liquidsbut not all liquids. Specifically problems may arise when attempting tofilter air through a filter when urine is in contact with the other sideof the filter. Whether urine possesses natural wetting agents andsediments which prevent functioning of the filter or whether the lack offunction is due to some other characteristic of urine is not known. Ihave found, however, that some filters which function well and filterthe air in allowing it to pass through and into water on the oppositeside do not function when urine is the fluid on the opposite side.However, I have found that all such bacterial filters even cotton plugsare effective if there is interposed a porous material which is fluidimpervious but will pass air. Moreover, I have designed simple apparatuswhich will permit me to determine whether a filter needs to be protectedfrom contact with urine or other body fluids. My invention, therefore,includes all bacteria] filter means as is illustrated by typicalexamples shown in the drawings and described herein.

Referring once more to the drawings:

In FIGURE 1, a typical drainage system of the invention is shownincluding a retentive catheter of the selfinflating type but modified bythe inclusion of a bacterial filter aerating channel 21 which terminatesin a side arm 20, containing a filter unit 23. The drainage systemcatheter illustrated in FIGURE 1 has a flexible insertion main arm 11which terminates in a tip 11a containing a drainage eye 13. The eyeextends through the tip and intersects the main drainage channel 12.This channel extends from the intersection with the eye through thelength of the catheter including the connection bell 11b. Two side arms14 and 20 contain the inflation reservoir 14a and the filter bell 20a,respectively. Side arm 14 is terminated by a plug 15 and when thereservoir 14a is inflated as shown, a clamp 16 prevents release of thefluid from the reservoir. The side arm 14 contains a channel 17 whichconnects with an opening 18 in the main arm wall within a sealed bag 19.Upon release of the clamp 16, bag 19 is inflated by the fluid forced outby contraction of the reservoir 14a to become the retention means.

Side arm 20 contains a channel 21 which leads to an eye 22 in the tip ofthe catheter. Side arm 20 also contains a filter unit 23 of the typeillustrated in FIGURE 12 which is retained by the stretched bell 20a.

The longitudinal section depicted in FIGURE 2 shows the connectionsbetween the channels 12, 17 and 21 and their respective eyes 13, 18 and22.

In the drainage system as shown in FIGURE 1, the air enters the filterunit 23 and the latter extracts the bacteria. Bacteria-free air thenpasses down the channel 21 and into the bladder itself overcoming thenegative pressure as the urine is pulled into the main drainage channel12.

In FIGURE 3 is illustrated what is perhaps the preferred catheter tipfor those urine or other fluid drainage systems in which the filter unitis arranged to be a part of the catheter itself as opposed to a systemsuch as that shown in FIGURE 8. In FIGURE 3, the channel 210 connectswith the filter unit at the exterior end of the catheter and with themain drainage channel 12a by an opening 24 behind the eye 13a.Preferably, the opening 24 is pointed in the direction of urine flow. Asthe air enters due to suction as the urine or other fluid moves past,the negative pressure is broken.

The retention bag or balloon 19a, its eye 18a and its channel 17a aresimilar to those of FIGURE 1.

In FIGURE 4 is illustrated a further modification of the inventionwherein the aeration channel 21b in side arm 20b opens into the maindrainage channel 12b near the bell of the catheter. In thismodification, the reservoir arm 14b and its channel 17b are unchangedand the catheter inwardly of the channel 21b is similar to that of aregular Foley inflatable retention catheter. The filter unit 29 consistsof a tubular adapter 29a having a female end for receiving side arm Ztiband a male threaded end to which is screwed a perforated filter cap 2%containing the bacterial filter 290. This arrangement permits readyreplacement of the filter and its perforated cap.

In FIGURE 5, a modification of the drainage system of FIGURE 4illustrates a filter unit 230 into which the side arm 200 is insertedlike a stopper thus connecting the filter unit to the main drainagechannel 120 by means of the side arm aerating channel 210. Again thereservoir side arm 14c and its channel 17c are unchanged. Again inwardlyof channel 210 the catheter resembles a regular Foley inflatableretention catheter.

FIGURE 6 and its longitudinal enlarged section FIG- URE 7 show amodification of FIGURE 4 in which there is no filter side arm, butrather an opening 25 through the main arm into the main drainage channel12d. The patch 26 containing the filter 27 which covers the hole 25 maybe cementedyvulcanized or otherwise adhered or sealed in place, to thecatheter wall by the seals 28. Inwardly of the filter the catheter is atypical Foley inflatable retentive catheter with the usual side arm 14dcontaining an inflation channel 17d.

FIGURE 8 illustrates a typical drainage system of the inventionutilizing a regular Foly inflatable retention catheter 30 including areservoir side arm 31 and a connecting bell 32. A Y fitting 33 havingtapered ends is fitted into the drainage tubing 34 at one end and intothe catheter bell 32 at the other end. The channel on the filter arm 35opens into the main channel 36. Preferably, the arm 35 points with theurine flow. Its open end is also slightly tapered and it makes a goodseal with the filter holder 37 which contains the sealed-in filter 38.

FIGURE 9 illustrates a portion of a main drainage channel of a urine orother body fluid drainage system 40 including a side arm 41 containingan end plug 42, a filter unit including a hollow needle 43, a filterholder 44 and a sealed-infilter 45. The needle 43 is shown inserted intothe plug to permit aeration with bacteria-free air.

Obviously, the filter units of FIGURES 4, 5, 8, 9 and 15 may be replacedvery readily. The other filters. with the exception of that shown inFIGURES 6, 7 and 10, may be replaced if they become clogged but withmore difficulty.

In FIGURE 10 a filter unit operating under the maze principle firstdemonstrated by Pasteur is shown attached to aerate the main drainagechannel 52 of the drainage system 50. The filter'unit consists of asmall hollow tube 51 which is adhered to a main drainage tube 54 andmakes a number of spiral convolutions about it. The end of the smalltube is preferably pointed in the direction of urine flow as it issealed projecting into the main drainage channel 52.

FIGURE 11 illustrates a filter unit 55 which consists of a bacterialfilter 57 of some fibrous material such as cotton which is operative asa filter only so long as it remains relatively dry. This filter iscontained in a plastic cup 56 having a porous end 58. The end portion 58must be capable of passing air but not of passing liquid. This porousmaterial as well as the bacterial filter proper may be tested foroperativeness by the device of FIGURE 16.

FIGURE 12 illustrates a filter unit 60 similar to FIG- URE 11 but theplastic cup 61 with its porous end 63 has a sheet type filter 62 sealedover its open end.

FIGURE 13 illustrates a non-porous tube 65 with one open end stopperedwith a porous open-celled foam plug 66. It is necessary that the plugnot drip body fluid while it admits air. The other open end of the tube65 may be closed with any type of bacterial filter preferably separatedfrom the plug.

FIGURE 14 illustrates the preferred type of filter unit 70 in which aholder 71 is open at one end and closed at the other by asealed-in-place filter 72 With this type of filter the body fluids,including such fluids as urine, actually contact one side of the filteritself.

In FIGURE 15 is shown a fail-safe type drainge system in which a maindrainage tube 101 has a bifurcated side arm 102, the arms of whichterminate in primary filter unit 103 and secondary filter unit 103a.Unit 103a includes a ball check valve 104 with ball 105 shown seated inits hemispherical seat. When the primary unit fails to reduce thenegative pressure for some reason, the ball 105 is lifted off its seatand air is pulled in around the ball to relieve the negative pressure. Agrid 106 prevents excessive movement of the ball. Obviously, when theball is displaced from its seat for any reason, the filter is open. Thesecondary unit should be so placed, therefore, as to be closed bygravity when the patient is in his predominate attitude and the primaryunit is operative.

In FIGURE 16 is shown a testing unit by which bacterial filter elementsmay be tested. The unit consists of a Foley type catheter 80 in whichthe main channel 76 terminates in drainage eyes 74 and 74a. Side arm 81includes channel 73 which latter terminates at the openings 73a withinthe retention bulb 78. A toy balloon 77, which prior to the test isfilled with 200 to 400 cubic centimeters of fresh body fluid such asurine to assume the dotted inflated position is retained in the filledcondition when the bulb 78 is inflated so long as clamp 93 is occludingchannel 76. The Foley catheter used my be one in which there is noreservoir 79 as indicated but rather the retaining bulb 7 8 is inflatedby a syringe without inflation of the reservoir 79. With automaticallyinflatable catheters, however, the reservoir 79 is inflated and theretained fluid later released to inflate the retention bulb 78. Insertedinto the bell the catheter 80 is a hollow fitting 82 which leads fromthe main drainage channel 76 into three separate channels, one leadingthrough tubing 85 to a U tube manometer 86 with open end 75 andcontaining mercury, one leading through tubing 83 to a drainagereceptacle 84 and the other leading through tubing 87 to filter holdedunit 90 shown in enlarged section in FIGURE '17. The unit 90 consists ofan open female threaded ring 89' and a male threaded filter platform 88.The testing unit may be utilized to test not only sheeted and wadlikefilters but also the porosity of the ends of porous-ended filter cups.The material 91, therefore, may be any porous material which may besufliciently compressible to make a seal. In practice, the filledballoon 77 is elevated so that about 8-10 inches of vertical distancefrom catheter eye 74 to tubing 87 exists. The material to be tested isinserted into the female ring 89 which is then screwed down to form aseal with the sealing ring 92 on the filter platform.

The clamp 94 which is shown open in FIGURE 16 is closed for this testand the clamp 9.3 is then opened exposing the material to be tested tothe vertical head of 8 to 10 inches of body fluid. If no fluid haspenetrated the material being tested within a minimum of 30 minutes, thematerial is satisfactory so far as leakage of fluid is concerned. Thenext test is for porosity. Before opening clamp 94, note that themanometer indicates a positive pressure in millimeters of mercury. Ifthe material being tested is not porous, as soon as clamp 94 is opened,the manometer will indicate a negative pressure dependent upon theentire vertical height of the fluid. If the material being tested isporous, air bubbles will be drawn into the pipe 82 and the negativepressure will be broken at that point. The manometer will indicate areduction of negative pressure in millimeters of mercury to a pointequivalent to the 810 inches of vertical head from the filter used inthis test. By lowering the balloon 77 to about 3 inches a negativepressure is achieved similar to that one might expect with the filterworking during a urinary catheterization with the patient in supineposition. Where the patient is ambulatory and a vertical head of 8-10inches of urine might exist above a filter unit placed near the bell ofthe catheter, pseudo polyps may be formed in the bladder. Catheters ofthe type illustrated in FIGURES 1, 2 and 3, especially the latter wouldbe very much preferred because these catheters break the negativepressure regardless of patients attitude at a point which would preventformation of such pseudopolyps.

Those bacterial filters which cease to function to admit air when bodyfluids are directly in contact with their inner surfaces and those whichcease to be bacterial filters because of wetting are suitable when theyare used with a porous-ended filter cup, the end of which is materialwhich does not show body fluid on the outer surface during the test.

Obviously, the seal between the filter unit and its side arm channelmust be fluid tight. This can be accomplished by friction fitting ofelastic side arm material by solvent sealing, by heat sealing and otherwell-known methods. Likewise the filter may be retained hermeticallyleakproof in its holder or porous-ended cup or in position on the maindrainage system by these and other well-known methods.

Of the materials demonstrated by the apparatus of FIGURE 16 to besuitable as a shield to prevent body fluid from contacting the bacterialfilter, polyolefins are generally superior when they are used in properpore size and open area. A preferred shield material is porouspolyethylene obtainable from Porex Materials Corporation of F airburn,Ga. The material which has been used with excellent success is aboutinch thick and has an open area of about 50% composed of relativelystraight channels each about 3040 microns in diameter. This materialwill hold a head of 8l0 inches of body fluid without leaking while airis passing through. The porous material may be used as the end portionof a filter cup or it may be se cured to the tubing itself but it mustbe secured in a leaktight manner and be interposed between the bodyfluid and the bacterial filter when the latter will not function whencontacted by body fluid.

Bacterial filters are available from a number of sources. Generally,they consist of a framework of woven or other mesh-like material towhich is joined the filter proper which is a usually very fine-poredfilmlike material. Other bacterial filters are made from nonwovenmaterial with the fibers coated or treated to make them resistant tovarious liquids. One source of bacterial filters is the PallflexCorporation which can be contacted at the Pall Trinity 00., Putnam,Conn. Another source is the Gelman Instrument Co., 600 S. Wagner Road,Ann Arbor, Mich. Cutter Laboratories at Berkeley, Calif, and AbbottLaboratories of North Chicago, Ill. also manufacture bacterial filters.In any event I prefer to test the bacterial filter on the apparatus ofFIGURE 16. In most cases it is very difficult to obtain information onthe precise construction and materials of which a particular filter ismade. An exception to this is the filter revealed in the above mentionedCanadian patent. With the apparatus, however, it is unnecessary to domore than run a test. Most bacterial filters will give excellent servicewhen they are kept separated from the body fluids and in the absence oftesting equipment (which is quite simple and inexpensive) it isadvisable to use a porous shield impervious to body fluids but perviousto air with all filters.

By bacterial filter I intend to include a filter capable of filteringone or more micro organisms from the air passing through it.

I claim:

1. In a catheter having a distal end for inserting into an animal bodycavity to be drained of fluids and an outward proximal end and having anannular tubular wall defining a drainage channel, the improvementcomprising in combination therewith a vent opening through said annularwall at a point intermediate the ends thereof and a bacterial filterconnected to said vent, said filter being impervious to body fluids andpervious to air, and positioned to filter air entering said vent.

2. A catheter in accordance with claim 1 wherein a static shield meansis provided, positioned between the filter and the vent, said shieldmeans being pervious to air but impervious to body fluids.

3. A catheter in accordance with claim 1 wherein the vent is positionedin the annular tubular wall along the proximal end thereof and thefilter is positioned to filter air entering said vent.

4. A catheter in accordance with claim 1 wherein the annular tubularwall member includes a separate aeration channel extending the lengththereof and terminating in a side arm projection at the proximal endthereof and a separate orifice at the distal end thereof, and having abacterial filter positioned to filter air as it passes through the sidearm channel.

5. A catheter in accordance with claim 1 wherein the vent comprises aside arm projection positioned at the proximal end of the annulartubular wall member defining an aeration channel communicating with thedrainage channel and having the bacterial filter positioned to filterthe air as it passes through the side arm channel.

6. A catheter in accordance with claim 2 wherein said static shieldmeans comprises a material which is pervious to air and impervious tobody fluids interposed between the bacterial filter and the vent.

7. A catheter in accordance with claim 2 wherein said static shieldmeans comprises a hollow rigid retainer for carrying the filter andhaving a wall member interposed between the bacterial filter and thevent, said wall member being pervious to air and impervious to bodyfluids.

8. A catheter in accordance with claim 4 wherein the bacterial filter iscarried by a relatively rigid retainer having an air pervious-body fluidimpervious wall member interposed between the filter and the vent, saidretainer disengageably fitted to the side arm projection.

9. A catheter in accordance with claim 4 wherein the side arm terminatesin a relatively rigid retainer portion having a wall member separatingthe aeration channel from the retainer portion, said wall member beingpervious to air and impervious to body fluids, and a bacterial filterdisengageably fitted within the retainer portionsaid filter beingseparated from the vent by the air previous-body fluid impervious wallmember.

10. A catheter in accordance with claim 1 wherein the drainage channelincludes a secondary vent opening having a bacterial filter connected tosaid vent, said filter being pervious to air and impervious to bodyfluids and positioned to filter air entering said vent, said secondaryvent being designed to introduce filtered air into the drainage channelof the primary vent and filter fails to function.

11. In a catheter, for use in conjunction with a urinary collectionsystem, having a distal end for inserting into an animal body cavity tobe drained of fluids and an outward proximal end terminating in bellportion at said end and having an annular tubular wall defining adrainage channel, the improvement comprising in combination therewith alength of tubing having a main channel therethrough engageable at itsone end within the catheter bell such that the channel communicates withthe drainage channel of the catheter and at its other end with theurinary collection system, said tubing having a vent openingtherethrough at a point intermediate the ends thereof and a bacterialfilter connected to said vent being pervious to air but impervious tobody fluids and positioned to filter air entering said vent.

12. A catheter in accordance with claim 11 wherein the vent comprises aside arm projection positioned between the ends of the length of tubing,said side arm projection defining an aeration channel communication withthe main channel thereof and having a bacterial filter positioned tofilter air as it passes through the side arm aeration channel.

13. In a catheter having a distal end for inserting into an animal bodycavity to be drained of fluids and an outward proximal end, and havingan annular tubular wall defining a drainage channel, the improvementcomprising in combination therewith a vent and bacterial filter unitconsisting of a relatively smaller open tube-like conduit wound inspiraloid convolutions about a portion of the annular tubular wallproximate the proximal end thereof, said conduit having an end openingthrough said tubular wall so as to point in the direction of drainageflow through the drainage channel.

References Cited UNITED STATES PATENTS 2,560,915 7/1951 Bamberger 1283502,930,378 3/1960 Buyers 128350 3,114,373 12/1963 Andersen 1283503,157,481 11/1964 Bujan 55417 3,275,001 9/1966 Rosecrans 128349 DALTONL. TRULUCK, Primary Examiner.

US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,429,314 February 25, 1969 Richard E. Ericson It is certified thaterror appears in the above identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 49, "or" should read of Column 4, line 40, after "may"insert also Column 5, line 23, "my" should read may Column 7, line 38,"previ-" should read pervi- Signed and sealed this 14th day of April1970.

(SEAL) Attest:

Edward M. Fletcher, 11'. E.

Attesting Officer Commissioner of Patents

